Improvement in air-pumps



PATENTBD MAY 26, 1863.

R. PORTER.

AIR PUMP.

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UNITED STATES nUFUs PORTER., On'MELnOsE, Assienort vTO THOMAS E. wELLs, OF Rox- PATENT (1-"FICE,

BURY, MASSACHUSETTS.

IMPROVEMENT IN AIR-PUMPS.

Specification forming part of Letters Patent No. 38,7] 5, dated May 26, 1863 5 antedate October 2, 1862.

To all whom it may concern:

Be it known that I, RUFUs PORTER, of Melrose, in the county of Middlesex and State of Massachusetts, have invented a new and useful Improvement in Air-Pumps; and I do hereby declare that the following is a full and exact description of the same, reference being had to the annexed drawings, making part of this specification, in which- Figure l is a front elevation. Fig. 2 is a horizontal section on the line o o of Fig. l. Fig. 3 isa central vertical section; and Fig. 4 represents the periphery of the grooved cam-cylinder, extended in the form of a plane.

The nature of this invention consists of an arrangement of mechanism whereby the pistons of six (more or less) air-pumps are operated by means of a grooved cylindrical cam in such a manner that the force applied shall encounter a uniform resistance, and produce, if so required, a uniform bla-st or discharge of compressed air.

To a hollow platform, A, (which constitutes an air-chamber,) are attached a concentric series of vertical cylinders or pump-barrels, B, each of which is furnished with a valved piston, C, Of ordinary construction, and each communicating with 'the air-chamber A. To each piston is attached a piston-rod, D, which extends upward through an annular guideplate,.E, and to the centerward side of which is connected an anti-friction pulley, F. Upon the center of the platform A stands a vertical shaft, G, upon which is mounted a cam-cylinder, H, in the periphery of which is an irregular circumferential groove, c b ed, of sufcient width and depth to admit the pulleys F to play freely therein, so that a vertical vibratory motion of the several pistonsis produced by a rotary motion of the shaft G, the

' relative diameter of the cam-cylinder being such that the irregular groove receives all of the pulleys, and operates them all. at the same time.

'Ihe peculiar form and direction of the circumferential groove are plainlyrepresented in Fig. 4, by which it may be seen that the descent of each piston is so graduated that its Y most rapid motion is at the commencement,

K, and upon which may be mounted a iiywheel, if occasion requires.

The anti-friction pulleys F are so connected to the piston-rods E that one or more of them may be readily detached whenever the operation of a less number of pistons is required, the pivot e, upon which each pulley is mounted, being inserted from the outward side of the piston-rod, and secured in its place by having a screw-thread extending a part of its length, as represented in Fig. 3. The compressed air is discharged through the tube M.

Instead of the irregular groove c b c d, the cam-cylinder may be furnished with an irregular circumferential flange, and each piston-rod being furnished with two pulleys-the one above the other-tlie angemay work between them for the purpose of operating the pistons; or the cam-cylinder may terminate below, at the line of the upper side of the groove, so as to depress the pistons only and let them be elevated by a series of helical or other springs.

Two, three, or four crank-shafts, S, may be employed on opposite or different sides of the central shaft, G, each shaft S being furnished with a gear-wheel, J, all meshing into the same horizontal gear-wheel, I, so that two or more men may be employed at the several cranks at the same time. Two or more dischargingtubes, M, may also be employed, if occasion so requires.

What I claim as my invention, and desire to secure by Letters Patent, is-

l. The operating of a concentric series of pump-pistons by means of a central cam-cylinder, the axle of which is parallel to the rods of said pistons, substantially as shown and structed and arranged substantially in the described. manner and for the purpose herein set forth.

2. The axlepivots e, constructed as herein described,in combination with the piston-rods BUFUS PORTER.

D and pulleys F. fitnesses 3. The combination of the cam cylinder H DAVID T. MARSTON, with a. concentric series of air-pumps, con- RANDOLPH L. STICKNEY. 

